Validation on field not working as expected

Hello,

I am currently experiencing some rather unexpected behaviour, where it only works every third time. If I click the Save button X times in a row, it only works every third time.

Code:

// ProductExternalReviews.ts
import { CollectionConfig } from 'payload/types';

import { validateYoutubeUrl } from '../utilities/helpers';
import Products from './Products';

const ProductExternalReviews: CollectionConfig = {
  slug: 'product-external-reviews',
  access: {
    read: () => true,
  },
  versions: true,
  fields: [
    // Main
    {
      name: 'product',
      type: 'relationship',
      required: true,
      relationTo: Products.slug,
      index: true,
      admin: {
        description: 'In case it is a bundle, select the main product',
      },
    },
    {
      name: 'type',
      type: 'select',
      required: true,
      defaultValue: 'youtube-video-url',
      options: [{ label: 'Youtube Video URL', value: 'youtube-video-url' }],
    },
    {
      name: 'youtubeVideoUrl',
      type: 'text',
      required: true,
      admin: {
        condition: (_, siblingData) => siblingData?.type === 'youtube-video-url',
      },
      validate: validateYoutubeUrl,
    },
  ],
};

export default ProductExternalReviews;

// helpers.ts
const youtubeUrlRegex = /^(https?\:\/\/)?(www\.youtube\.com|youtu\.?be)\/.+$/g;
export const validateYoutubeUrl = (value: string) => {
  if (!youtubeUrlRegex.test(value)) {
    return 'Invalid Youtube URL';
  }

  return true;
};

What am I doing wrong here?